The U.S. Forest Service says cloudy skies and lower temperatures have slowed the spread of two forest wildfires that are threatening as many as 250 homes in far Northern California.

The Forest Service reported Sunday that the fires had burned 98 square miles in the Klamath National Forest by Sunday. That was 8 square miles more than a day earlier, but represented a significant reduction in the growth of the blazes that had picked up steam as humidity declined and winds increased late last week.

The two wildfires are the largest among 17 that were sparked by lightning in the forest on Aug. 11. They remained 15 percent contained.

More than 2,100 firefighters and 19 helicopters are taking advantage of the better weather by laying hoses, constructing fire lines and clearing brush from around evacuated communities.